Help 379 ,,550 ,,3406e truck just idles i thought it

was the throttle sensor,,changed it,,,2months later it went again... changed it again,, it went 2 weeks later ???it did go the sensor is ok ,,$500 and Pete couldn't find nothing but the truck does run now it just decided to run good ,,,they check the wire from the petal to the ecm ,,is good ????any help

 

I think they did some thing like by pass some thing and cant tell me cause ,,you know their not suppose to by pass anything,,a Freight liner mechanic i had used would tell me they couldnt fix the problem unless the by pass something so id say do what you got to do i dont know nothing

 

Thanks guys the pedel connection was it a big tx